Lubricating composition



Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE LUBRICATING COMPOSITION No Drawing. Application August 26, 1939, Serial No. 292,068

8 Claims. (01. 252-32) This invention relates to high molecular weight halogenated organic. compounds and methods of preparing same. More particularly, it relates to the halogenation of high molecular weight hydrocarbon polymers such as those produced by the polymerization of isobutylene at low temperature, generally below 0 C'. and preferably as low as 10, 20 C., or even 80 C., in the presence of boron fluoride or other halide polymerizing v catalyst effective at such low temperature.

This application is a'continuation-in-part of application Serial No. 170,120 filed October 20, 1937, Pat. No. 2,181,144, which is a continuationin-part of application Serial No. 749,072 filed October 19, 1934.

It has been discovered that such polymers, which may range from 1,000 or so up to 15,000, 20,000 or even 250,000 or more in molecular weight (determined by the viscosity method described in Staudingers Book, Die Hochmolekularen Organischem Verbindungen, H. Staudinger Berlin 1932 Verlag Von Julius Stringer, page 56), are very stable and relatively inert chemical compounds, being substantially completely saturated with re- 'spect to hydrogen and having a very low iodine number, e. g. about 7 or less. Generally, the higher the molecular weight the more chemically inert are these polymers. For instance, they are substantially not aiiected by sulfuric acid and they are very resistant to oxidation, sulfurization,

and many other chemical treatments. They differ from rubber which is quite unsaturated in that they cannot be vulcanized by sulfur while rubber can, and in that they are soluble in all proportions in petroleum hydrocarbons, such as naphtha, kerosene and lubricating oils, causing an increase in the true viscosity and viscosity index thereof, while rubber forms a gel (merely swells) in those liquids.

Other similar materials which may be treated according to this invention include any similar substantially saturated high molecular weight polymers which may be considered to have a chemical structure corresponding to that of a very 5 long chain of carbon atoms containing occasional side chains of alkyl groups, such as methyl, ethyl, etc. Besides isobutylene, other iso-olefines, such as iso-amylene, especially methyl-2 butene- 1, may be polymerized at low temperature, to produce high molecular weight polymers for use as raw material for this invention. Although the above type of material is preferred, other materials believed to have a substantially similar chemical structure but'formed in other ways may be used in some instances, for example, hydro-rubber (which is produced by destructive hydrogenation of rubber and is entirely different from theparent substance in its properties and behavior).

According to the present invention, high molecular weight halogenated compounds are prepared by contacting a halogen with a solution of'a high molecular weight hydrocarbon of the structure described. The solvent to be used may be any one which is non-reactive with the halogen being used or which, if reactive therewith, will not cause any harmful effect on the high molecular weight product. Carbon tetrachloride has been found very suitable. Other solvents, such as sulfur halides, etc., may be used. The solvents must be sufficiently fluid that a solution of the high mo- 15 lecular weight hydrocarbon therein will not be too viscous for treatment with the halogen under the conditions of treatment. The halogen to be used may be any one of the four, 1. e., fluorine,

. chlorine, bromine or iodine, although chlorine is 20 the cheapest and most practical.

The halogenation may be carried out at room temperature or elevated temperature, such as up to 50 or C., but should not be too high inasmuch as halogenation at an excessively high 25 temperature will cause excessive breakdown of the molecular weight of the product. The halogenation may be carried out at atmospheric pressure or considerably higher pressures, such as 5 to 50 or 100 atmospheres or more, especially when 3 carrying out the reaction at low temperature.

The halogenation is preferably carried out in the presence'of strong light such as ultraviolet light or direct sunlight, although it will proceed at a slower rate in'diffused light and even to a 35 slight extent in total darkness at ordinary temperature and pressure and will proceed even quite rapidly at more elevated temperature and pressure even in the absence of light. One effect of carrying out the halogenation in the presence of 40 light and particularly at low temperatures such as 0 C. or 20 C., 40 C., etc. is that there is less tendency for the polymer to be broken down in molecular Weight during the halogenation. The conditions to be used during. halogenation 45 will therefore depend to some extent upon the ype of product desired for incorporation to the lubricating oil. For instance, if it is desired to use a chlorinated polymer having a high thickening and viscosity index improving property, it is 50 preferable to carry out the chlorination in' the presence of strong light at low temperature and of course not carry the chlorination beyond the point of solubility in the lubricating oil base stock to be used. (The limit is about 10% to 12% of 5a chlorine in polymers having a molecular weight of 50,000 or 100,000 or more whlchhave not been.

seriously depolymerized during chlorination.) n the other hand, if it isdesired primarily to haveg achlorinated polymer having a high chlo-t or more in thedark by the aid of heat and pressure, or to use a polymerzhaving a substantially lower molecular weight, such as.1,000\ to 20,000 or 30,000, as the starting, material, andcarry out i the chlorination either with. or withoutiight.

ence of peroxides, e.1g.]bennoylperoxide,. todie.

rect thehalogen atoms preferentially to the alpha U (end) carbon atoms in hydrocarbon molecules. The percent of halogen incorporated depends up-jon the duration of the treatment. Generally, it is desirable to incorporate from 5 or-% to l of halogen, although aslittlelas 1% and as much as 50% may beincorporated if desired It is possible to chlorinate polyisobutylene to even greater chlorine content such as 60, 65, "10 or even 75% chlorine but such products are not as solu-r bleinpetroleuml ricating oil fractionsasare the chlorinated p ymerscontaining 10% for less:

of chlorine.

The chlorlnatedisobutylene polymers a low chlorine content. (loitoio'k ior lower) and those having a high chlorine content (substantially above 150%) areboth substantially more soluble in aliphatic petroleum hydrocarbonliq: uidsthan are the polymershaving intermediate chlorine content. a The polymers oi all: degrees of chlorination are quite readily isoluble in :petroleum. fractions. containing aromatic compounds, such as sulfur, dioxide extractsof =pe-; troleum distillatea, Incorporation of; polymers in nonaromatic petroleum fractions. may befacilie tated by the use of mutuaisolventssuch arc-1 matic hydrocarbons, chlorinated low molecular:

weight aliphatic hydrocarbonahetones or esters.

Various methodsmay belused for treatingthe high molecular weight hydrocarbon, withthe hale ogen; For. example, .chlorine may; be bubbled through a carbon tetrachloride solution .of-the high molecular weight polymer or chlorine I may be. subjected to acountercurrent Jpn-10f a solution of the polymer. Anothenaliernativeis to carry out the halogenationtreatment inthe presence of bases. e calcium or magnesium oxides or carbonates, sodium carbonate or bicarbonate, etc., or over watercontainingan insoluble carbonate, such as calcium. carbonate or magnuium carbonate, for the purposeof absorbing hydrogen chloride liberated bythe reaction. 1,

the original polymerization of isobutylene, for example, may be carried out inthe presence of carbon tetrachloride or other solventwhich will be. suitable for the halogenation and then aslsoon as the polymerization process is. completed the solutionof the highmolecular weight polymer may be treated immediately with a desired halogen, thereby avoiding the removal of the solvent used during the polymerization step and subsequent redissolving of the polymer in a solvent for the halogenation step. i

If desired, after the halogenation has been completed, the solution may be blown with air or ride. Any traces stillremaining may be removed byfurther blowing the liquidwith ammonia, or 5 other volatile amine, .aloneor mixed with air or inertgas, preferably atroom temperature or per- .haps up to 40' or 50" C.

alternativmthe product may be washed oneor more times with dilute alkali, such as causticsoda, inordertoremove any free hydro- 1 gen chloriderem aining as a result of the halogen f: treatment. "It vmayifalso, under some circum- Iodine may beused as a=catalyst.: If desired. the halogenation may outin the. presstances, be'desirable to heat the chlorinatedpolymer-at a low; temperature with a basicmaterial,

' such .1 as alcoholic potash. aqueous calcium hydroxide, sodium carbonatesolution, sodium bicarbonatefetc, to remove one or possibly more halogen -;atoms and thereby produce a further stabilinedproduct. Aldiincultly .volatile; basic 20 compound, preferably an aromatic amino such as monoethyl aniline or methyl naphthyl amine, may lbeadded as taestabilizer. (in proportions of 0.1to v1% or so). totheflnished halogenated hy drocar-bon. w

l The products prepared: accordingto the present invention high. molecular weight .halogenated hydrocarbons-and their physicalwproperties depend upon. the naturelof the originalmaterlaltreated and the duration and type of l treatment. These products maybe used for awide variety .of purposes: for instance, they may be condensed with aromatic hydrocarbons in the presence ofaluminumchloride, boron fluoride or other condensing agents, toproduce materials suitable aas lubricants orblending agents lill lubricants, such as: pour depressors, or they may be used for. any vother type of condensation reactions .in which halogenated aliphatic hydrocarbonsareused asoneoi thereaetants.

These-halogenatedwproducts, which can be prepared according tothisinvention, may. frequently serve to advantage as solvents or plasticizers. 'I'ior delustering gartificial silk, these high molecular weight, halogenatedpolymers may be mixed with M an inert organicqmaterial of an oily or waxy nature, such as petroleum oil, petroleum Jellyand and. the mixture added to solutions of artificialsilktobespun. l Many other useswill no doubt occur to those skilled in-the art and it lsanuoblect of the present invention to claimpbroadly these high molecular, weighthalogenated products preparedfroin substantially saturated organic compounds having a structure represented by a long straight chain of carbon 1 atoms with a pl l fl-lity of aikyl side chains and containing a substantial proportion of halogen atoms incorporated I according to this invention regardless of the purpose forwhich theyaretobeusedp v I. n I

The invention willtbe' illustrated from the following examples: I l l q M Examplel 1 Chlorine gas is diffused at room temperature in ordinary diffused light, through a solution of carbon tetrachloride. containing, dissolved therein, about 20% bra-hydrocarbon polymer having a molecular weight of about 8,000 andprepared by polymerizing isobutylene at a temperature of -20 C with boron fluoride as catalyst. When about20% of chlorine has been combined chemically with the polymer the chlorination is stopped and the product is washed withwater and the carbon tetrachloride removed by distilla tion.

The product of this experiment diifers from chlorinated rubber in that (1) rubber containing small amounts of chlorine is unstable, while the present product is relatively stable, (2) no solid 6 chlorinated products were obtained as in the chlorination of rubber, and (3) the present product is miscible with paraflin wax while chlorinated rubber is not. a

The chlorinated polymer, for example, may also be used in compounding high viscosity index extreme pressure lubricants either alone or in conjunction with sulfur or sulfur compounds or other materials known to the art in preparing extreme pressure lubricants.

The saturated high molecular weightpoiymers may also be mixed with wax, resins, mineral and vegetable oils, chloraromatics, esters, and the like, prior to or after halogenation. When blended in mineral oils, the chlorinated polymer may be used in conjunction with oxidation inhibiting amines, oiliness agents, thickene'rs, sludge dispersers, pour inhibitors, soaps, bright stocks, white oils, etc.

Example 2 When the isobutylene polymer is of a low molecular weight (around 3,000) the direct chlorinationis effected by passing chlorine gas through the polymer in the presence of very small amounts of iodine to catalyze the reaction. In this example no solvent is present and the resulting product requires only a slight carbonate washing to remove any of the remaining HCl.

Example 3 Chlorine gas is passed under pressure through vents in the bottom of a tower packed with broken porcelain or spiral packing; when the tower has become saturated with the chlorine gas a solution of isobutylene polymer in carbon tetrachloride isv sprayed in at the top 01' the tower passing down through the chlorine gas and being removed at the bottom of the tower and pumped back to the top of the same tower or other sim? ilar towers and the contact repeated .until the chlorine content has reached the required amount. 1

The gaseous mixture removed at the top is r scrubbed free of HCl by passing through solid caustic soda and again passed in at the bottom of the tower.

chlorinatedisobutylene polymer is washed free of H01 by a slight carbonate washing and thecarbon tetrachloride removed by distillation.

Example '4 150 grams of polymerized isobutylene (12,000 molecular weight) were dissolved-in 850'grams of carbon tetrachloride by heating (120-140" F.)

and stirring for 1 hours. After the polymerized isobutylene was completely dissolved, the solution was transferred to a separatory flask and 0.5 gram of iodine added. Chlorine gas was passed through the solution at a slow rate at room temperature ('75-80 F.) by means of .a small alundum thimble attached to a glass tube and suspended close to the stopcock end of the separatory flask. Chlorine was passed through the solution for 5% hours and then discontinued over night (about 16 hours). The following morning the chlorine was again passed through the solution for eight hours, and then again shut oil. The chlorine saturated material was allowed 7 to stand over the weekend (60 hours).

The carbon tetrachloride solution of.

A small sample (200 grams). of the carbon tetrachloride solution of the chlorinated product was placed in a filter flask, and the carbon tetrachloride distilled off at 200-'210 F. (water bath) under laboratory vacuum pressure, after which carbon dioxide was blown through.

The product was a'a' heavy viscous material, sim-' ilar to the original polymerized isobutylene and having a slight pink color due to iodine present.

. The product shown by analysis to contain 24% chlorine was found to becompletely soluble in petroleum ether and mineral lubricating'oil.

In the removal of traces of carbon tetrachloride from the washed solution of chlorinated isobutylene polymer in carbon tetrachloride, almost the .total amount of solvent is removed by mere distillation, either atmospheric or under reduced pressure, the remaining traces. of solvent being .re'moved'by dissolving the practically solvent-free chlorinated product in close out naphtha with a boiling range close to the boiling point of carbon tetrachloride (76 C.) and redistilling.

Example 5 Gaseous chlorine is dissolved in carbon tetrachloride solution of polyisobutylene (about 55,000 average mol. wt.) (ca 5%) at room temperature until approximately 10% by weight of the latter has been absorbed. The viscous solution is allowed to flow down the :wall of a cylindrical or conical vessel exposed to the radiation of a mercury vapor lamp (Uvirarc Type H-l) placed in the center. If the lamp is water jacketed,

'the rate of flow may be 5-8 cc. per second for complete reaction. The resultant solution is flashed to remove the major portion of the solvent and the chlorinated product precipitated by the addition of alcohol or acetone. The product is further purified by milling and'pressing. This product is soluble in petroleum lubricating oil distillates.

Example 6 of the lubricating ,oil and made a blend which was quite stable on standing and-had an excellent color.

Emmple 7 To the lubricating composition prepared in Example 6,- an addition of 7% of sulfur was incorporated and the resulting extreme pressure lubricant was found to contain 0.87% sulfur and 0.34% chlorine. Example 8 Polyisobutylene having amolecular weight of about 20,000 was chlorinated to about 15% chlorlne and it was added in several concentrations to a mineral lubrication oil base stock such as used in the preparation of greases. When the chlorinated polymer was present in 50% concentration, it was found to be soluble and the product was stringy. When theconcentrartion of chlorinated polymer was reduced to 10%, the grease blend still showed fair stringiness and when tested for load-carrying capacity it was found to carry 15 weights full load on the machine.

Example 9 A 4% solution othydro-rubber havinga molecular weight of about.10,000 was made in carbon tetrachloride. The solution was exposed tosun-r light and chlorinegaswas passedin through ;a bubblerat a temperature ranging from room temperature up to about '1 C. for 10. The 1 chlorination wascontinued for 3 or 4 hours until the addition 10!. a small amount oi petroleum ether caused cloud formation. It wasiound that the product contained about 10% of chlorine and was soluble in mineral lubricating oil.

Example 10 A Coastal oil washeated andfsmall piecesoi polyisobutylene of about 40,000 average molecular weight chlorinated to 5% byweigh-t. were dissolved into the oil by continuous stirringuntil about 5% of the chlorinated polymer was introduced."'1he results of the tests made were as follows: l

Viscosity Viscosit Viscosity at 100 F at 210 1 index Coastal oil .Q 210 4a. 5 g o Ditto+5% oi chlorpolymer. 844 96. 120

Hence it can be seen that by the additionroi only 5% of the chlorpolymer, it was possible to 1 convent a Coastal oil into an oil of a better and chlorinated with a slow stream of chlorine t in sunlight. Small samples were removed at intervals:v and diluted with petroleum :rether'.

When addition of petroleum ether gavea turbid solution, the chlorination 'was stopped and the. chlorinated product was recovered by precipitation with isopropyl alcohol and subsequent drying in a vacuum oven.

on Viscosity Viscosity Viscosity at 100 F. at 210 F. index Coastal oil 210 '43. 5 0 Ditto-+57 of chlorinated hydro-rubber 2. 240I 105 ill The amount of polymer added to the lubricant is generally about 05m 5% although amounts as low as 0.01% or as high as 10 orveven can be employed when conditions sorequire it.

The oil to which these halogenated polymers are added may benatural or synthetic oils of low or high molecular-weight such as petroleum lubricating oils, fatty oils, or oils produced by the polymerization of olenns. Such oils may be wan, dewaxed, treated by"; solvent extraction. acid, clay, or otherwise improved; residuals, pale oils .or light distlllates. .It is preferred to employ an oil of about 35'to 500Baybolt viscosity at 210' F.

Many of the above steps may be combined.

It is not intended that: the invention be limited to any of the specific examples given nor to any theories ,of the operation of the invention but in the appended claims it is intended to claim all inherent novelty in the invention as broadly as the prior art permits. 1

We claim:

1. A lubricatinl compositioncompi-ising a lubricating oil base stock and a halogen derivative of a substantially saturated linear aliphatic hya drocarbon compoundihaving a molecular weight above about 800 andcontalning atleast 1% of halogen.

2. Alubricating composition comprising a mineral lubricating oil and chlorinated polyisobutylenel 3. A lubricating composition comprising a mineral lubricating oil and ,a chlorine derivative of a polyisobutylene of at least 800 molecular weight. containing at least 1% of chlorine. M

4. A lubricating composition comprising a mineral: lubricating oil and an oil-soluble chlorinated hydrocarbon product obtained by'. chlorinatlnz polyisobutylene having a molecular. weight of 800-500,000 tolachlorine content of about 1-l5%.

5. A lubricating composition comprising a mineral lubricating oil and an oil-soluble chlorinated eral lubricating oil having a viscosity of 35-000. seconds Saybolt at2l0 F. and dissolved therein 0.1%. to 50% of chlorinated polyisobutylene.

8. A lubricating grease comprising a mineral lubricating oil base stock, metalsoap, and a chlorine derivative of a substantially saturated linear type aliphatic hydrocarbon compound having'a molecularwelght above about 800.

ARNOLD J. MORWAY. FLOYDL. MILLER. 

